High-intensity p40 immunostaining (3+) is inversely associated with patient survival.[24] Immunohistochemistry revealed abnormal expression of α-smooth muscle actin (SMA) in leiomyosarcoma,[25] rhabdomyosarcoma,[26] angiomyolipoma,[27] and other sarcoma tissues. Here, SMN1 is linked to rhabdomyosarcoma.